The present invention relates to a monitoring device for monitoring a system battery powering an external device, such as a two-way radio, when the motor is not running. During this time, the battery is discharged by the external device. A timer in the monitoring device allows the radio to run for a pre-set time. The device also includes a separate voltage detector which will override the timer and shut off the radio upon the detection of a low battery voltage as well as a vibration detector which detects vibrations from the engine to reset the timer whenever the motor is started.
The battery of the automobile powers CBs, AM/FM radios, two-way radios, radar devices and other electronic communication systems. A problem has developed from connecting numerous electronic equipment to the battery of the motor. This electronic equipment drains the car battery.
People who use communication systems in their cars or trucks need to leave the two-way radio, for example, on when the vehicle is unattended. With modern technology, this can include waiting for a page vehicle location detection by a control center, status reporting or in-coming data. The most common reason, however, is the inconvenience of manually turning the radio off each time one leaves the vehicle. Accordingly, people constantly forget at the end of the day to turn the radio off.